1. Field of the Invention
This invention relates to a chemical analysis apparatus for applying a sample material to a chemical analysis slide, i.e. a slide type chemical analysis device, provided with a single reagent layer or a plurality of reagent layers, maintaining the chemical analysis slide at a predetermined temperature (i.e. conducting incubation) for a predetermined time, and then optically measuring the degree of color formation in the chemical analysis slide for analysis of the sample material.
2. Description of the Prior Art
Qualitative or quantitative analysis of a specific chemical constituent in a liquid sample is generally conducted for various industrial purposes Particularly, it is very important in biochemical and clinical categories to quantitatively analyze chemical constituents or physical constituents in body fluid such as blood or urine.
In recent years, as disclosed in, for example, Japanese Patent Publication No. 53(1978)-21677 and Japanese Unexamined Patent Publication No. 55(1980)-164356, there has been developed and put into practice a dry type chemical analysis slide for quantitatively analyzing a specific chemical constituent or a specific physical constituent contained in a sample solution simply by applying a droplet of the sample solution With the chemical analysis slide, it is possible to analyze a sample solution more simply and more quickly than when the conventional wet type analysis method is used. Therefore, the use of the chemical analysis slide is desirable particularly in medical organizations, research laboratories, or the like where many samples are to be analyzed.
In order to analyze a chemical constituent or the like contained in a sample solution by use of the chemical analysis slide, a measured amount of the sample solution is put on the chemical analysis slide and is maintained at a predetermined temperature (i.e. incubated) for a predetermined time in an incubator to cause a color reaction, and the reflection optical density is measured by exposing the chemical analysis slide to measuring light having a wavelength selected in advance in accordance with the combination of the constituent of the sample solution with a reagent contained in the reagent layer of the chemical analysis slide. In this manner, it is possible to achieve quantitative analysis of the chemical constituent or the like.
In the medical organizations, research laboratories or the like, since many samples are to be analyzed, it is desirable that the analysis be conducted automatically and continuously. To satisfy this need, there have been proposed various chemical analysis apparatuses for carrying out sample analysis automatically and continuously by use of the aforesaid chemical analysis slides.
For example, it has been proposed in Japanese Unexamined Patent Publication No. 56(1981)-77746 to constitute a chemical analysis apparatus so that chemical analysis slides are disposed in an equally spaced relation to each other in the circumferential direction between two rotatable disks provided with an incubation heater for conducting incubation by the heater, the chemical analysis slide incubated for a predetermined time is positioned by rotation of the disks to face a read-out head disposed below the disks, and exposure of the chemical analysis slide to measuring light and measurement of reflection optical density are conducted by the read-out head via an opening in the bottom surface of the disk. With the proposed chemical analysis apparatus, it is possible to dispose a plurality of the chemical analysis slides in the circumferential direction between the two disks, and therefore to conduct analysis efficiently and quickly. However, the proposed chemical analysis apparatus has the drawbacks that the configurations of the disk rotation system and the control system for controlling the disk rotation system become complicated and the chemical analysis apparatus cannot be made very small and cheaply.
Also, as disclosed in Japanese Unexamined Patent Publication No. 58(1983)-21566, there has been proposed a chemical analysis apparatus wherein a conveyance path in a U-shaped form or the like is formed in an incubator, a plurality of chemical analysis slides supported by a carrier having a predetermined shape are sequentially fed into the conveyance path and conveyed along the conveyance path, and exposure of the chemical analysis slide, which has been incubated for a predetermined time in the conveyance path, to measuring light and measurement of reflection optical density are conducted by a read-out head disposed midway of the conveyance path. Also with the proposed chemical analysis apparatus, it is possible to conduct analysis efficiently and quickly by use of a plurality of the chemical analysis slides. However, since it is necessary to provide the mechanism for conveying the carriers supporting the chemical analysis slides along the conveyance path, the proposed chemical analysis apparatus is not completely suitable for making the apparatus small and decreasing the cost. Further, the proposed chemical analysis apparatus is not easily adaptable for measurement of the change rate of the reflection optical density conducted by measuring the reflection optical density of the same chemical analysis slide many times at predetermined time intervals.
In a different example of the chemical analysis apparatus, chemical analysis slides are sequentially fed and stacked in an incubator. After a predetermined time has elapsed, the stacked chemical analysis slides are sequentially fed out starting with the lowest slide and subjected to measurement of the reflection optical density. With this configuration, since the chemical analysis slides are stacked in the incubator, it is easy to conduct incubation and the incubator may be made small. However, the chemical analysis apparatus has the drawback that gas generated by the color reaction between a reagent of the chemical analysis slide with a sample applied to the chemical analysis slide while the chemical analysis slide is being incubated adversely affects the color reactions in the other chemical analysis slides, and the analysis accuracy becomes low. Also, with the chemical analysis apparatus, since the chemical analysis slides are sequentially fed out and subjected to the measurement after a predetermined time has elapsed, it is not always possible to conduct the measurement midway during the incubation. Therefore, the chemical analysis apparatus is not suitable for the measurement of the change rate of the reflection optical density.